Starting arrangement for fuel injection internal combustion engines



April 2, 1940. M. HURST ET AL STARTING ARRANGEMENT FOR FUEL INJECTION INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet 1 Filed March 3, 1938 A ril 2, 1940. M. HURST El AL v 2,195,927 STARTING ARRANGEIENT FOR INJECTION INTERNAL COMBUSTION ENGINES Filed March :5, 1958 2 Sheets-Sheet 2 Patented Apr. 2, 1940 PATENT OFFICE.

STARTING; ARRANGEMENT FOR FUEL INJECTION INTERNAL COMBUSTION ENGINES x Hurst, Stuttgart, Richard Hammer, Winneren, and Ernst Raithelhuber, Duren, Germany, assignors to Robert Bosch Gesellschaft mit be-i schrankter Haftung, Stuttgart, Germany Apphcation March 3, 1938, Serial No. 193,796

In Germany March 10, 1937 11 Claims. (01. m -1'19) In many starting up devices of injection internal combustion engines, it is diflicult to operate the starting up device for the engine simultaneously with the displacement of the movable stop of the member of the injection pump adjusting the delivery amount.- Thus for instance, with many electric hand switches of starters, the path of displacement of the movable part of the switch is too small, and the connection of adjustable members therewith is too awkward for-it to be possible to adjust the movable stop .by means of these members. Furthermore, it is desirable that the movable stop shouldreturn if possible at the end of the starting up process into the position in which at full load. it limits the path of the member adjusting the delivery amount and is also held firm in that position, so that,

' as long as the starting up device is disconnected, the stop cannot be displaced from this position,

and the member adjusting the delivery amount 7 pump and provided with pneumatic governing of the amount of fuel injected.

Figure 2 is an enlarged longitudinal section of a part of the arrangement of Figure 1.

Figure 3 is a modified arrangement for an injection internal combustion engine with. hand governing of the amount of fuel.

Figure 4 shows an enlarged longitudinal section through part of thisasecond form of construction.

a denotes a' four cylinder injection internal combustion engine and b denotes a toothed flywheel thereof. A pinion of an electric starting motor c,'which is connectedv through a lead d and a switch c to one pole of a storage battery I, engages. the toothed rim of the flywheel when it is desired to start the engine. The other Dole of the battery is connected to earth, as is the case for the starting motor. The'four outlets of the injection pump-g driven by the internal combustion engine are connected through pipes h with the fuel injection nozzles, which are accommodated in the cylinder heads and are not shown. To the injection pump there is connected a pipe 1', through which fuel' is supplied to the pump.

In the casing of the injection pump a "control rod k is displaceably mounted, and by means 5 of this rod the amount of fuel delivered to the separate pumps can be varied in known manner in the same way and at the same time. On the right hand side of the casing of the injection pump a casing t of a pneumatic governor is se- 10 'cured by flanges, in which casing a piston u connected with the control rod is of theinjection. pump can move, and this piston divides the inner space of the casing into two chambers. The left hand chamber is connected with the 15 atmosphere, while the right chamber is attached by means-of a flexible pipe 1; to a venturilike constriction 'of an intake pipe w which is fitted to the induction manifold. In the intake pipe w, seen in the direction of flow, there is v20 rotatably mounted in front of the constriction a throttle valve 11 which is coupled with the pedal q through a rod 1. The pedal is kept in the position shown by means of a spring s and in this position the spring keeps the throttle 25 valve approximately closed.) In the right hand chamber of the governorcasing t there is'ar-- ranged a spring n, which, when the throttle valve is completely opened, tends to displace the control rod late the left into the position shown, in

which position it" has adjusted the separate pumps to the full load delivery amount.

'On the left hand side of the casing of the injection pump there is secured a sleeve I which is open at the bottom and into which the left hand end of the control rod 7c projects. An electro-magnet 2 is fitted to a flange on the sleeve, which flange faces away from. the injection pump; this electromagnet is excited through the lead 3 after the switch e has been closed. As 40.

shown in Figure 2, the pot 4 of the electromagnet 2 issecured to the sleeve I by means of .an end disc 5, on which is seated a bush 3 in the bore of which the right hand end of a cylindrical armature 6 of the magnet is inserted and guided. The pot of the magnet encloses an annular coil I, which is arranged in an insulating sleeve 8. Inthe position shown of the armature, in which position the magnet coil is' not excited, the collar to arranged on the armature bears against the 50 left hand of the guidebush 9. The left hand part of the armature is reduced through a com cal' part 6b to a pin 60 of small diameter. The pin is carried through a bush l0 fitted in the cover of the pot, which bush is bored out coni-' ,i

cally relative to the conical part. Sb of the armature;

Over the end of the armature projecting into the sleeve I there is pushed a spring ll, of which the left hand support is the end disc 5 of the electro-magnet and of which the right hand support is formed by a spring plate I2 seated on the right hand end of the armature. In the position shown a round headed screw I3, which is screwed into this end of the armature'through the spring plate forms a stop for the left hand end of the control rod is of the injection pump; The round headed screw is secured by means of a lock-nut M, which holds the spring plate I2 firmly on the armature.

If the switch e is closed for the purpose of starting, then the coil 1 of the electro-magnet also receives current at the same time as the starter. Owing to excitation of the electromagnet, the armatureG is drawn out of the position shown against the force of the spring II to the left, until the conical part 6b ofthe armature abuts against the conical bored out portion of the bush Ill The screw I3 is thereby moved to the left into the position shown by dotted lines. As long as the engine has not yet been started up and no depression counteracting the return spring n is yet present in the induction manifold, the return spring n can move the control rod k to the left until its left hand end bears against the drawn back stop screw I3. In this position, the governing rod adjusts the separate pumps in such a manner that the greatest possible amount of fuel is injected into the cylinders.

Now if the driver opens the throttle valve in the induction manifold during starting, then the injection pump is already set to the delivery of the maximum amount, and, as long as the current depression in the induction manifold is still small, the return spring of the pneumatic regulator can keep the control rod is set in a position such that the pump will deliver the greatest amount of fuel.

As soon as the internal combustion engine has started the starter switch is opened again (position shown), so that the excitation of the electro-magnet ceases. The spring II then attempts to return the armature. 6 into the drawn out position shown. Since the depression in chamber t and the spring II are together more powerful than the return spring n, the control rod is also movedto the right again, the screw l3 limiting the movement of the control rod in such a way that the pneumatic governor can still set the injection pump to deliver at the most the fuel corresponding to the full load amount.

The spring ll tensioning the movable stop (armature) can also be used, at the same time c. g. with a-governing of the amount by means of a pneumatic governor as in Figure 1, for assimilating the delivery curve, (which rises with an increasing number of revolutions of the engine, of injection pumps withslide controlled inlets), to the combustion requirement curve ofthe internal combustion engine.

In the example of construction in Figure 3, the control rod 7:: of the injection pump g is directly connected with the pedal q by means of a bar 0, the left hand end of which is flexibly connected to the control rod is whilst the right hand end is similarly connected to the pedal. The spring s engaging the pedal tends to displacethe control rod to the position shown, in which it sets the separate pumps to a fuel delivery amount with which the engine can be kept running under no load.

On the casing of the starter motor c there is mounted a lever 01, one arm of which is flexibly connected to a sleeve member seated on the pinion shaft of the starter motor, and the'other arm of which carries a bridge contact piece, which can slide over a contact strip'cz with two contacts insulated from each other. The right hand contact of the strip is attached to a storage battery 1 and the left hand contact is attached to the 'electro-magnet 2'. I

The electromagnet 2 is fitted on the casing of the injection pump 9 as in the example in Figures 1 and 2, however, according to Figure 4, and differing from that construction there is attached to theleft hand end of the control rod 7:, (which .end projects into the sleeve I serving to secure the magnet 2 to the pump casing) a bush I5 of which the annularly bored left hand part 'pro- J'ects above the left hand end of the control rod 7c. In the projecting or surmounting annular portion of the bush there are provided two-bores, which are located on a diameter of the annular part and perpendicular to the longitudinal'axis of the governing bar and which guide two bolts IS. The mutually opposed ends of, the bolts l6 are bevelled off on the side remote from the control rod 70, and each carry an extension I! on the side facing the control rod. A spring l8 disposed across the extension I! tends to draw the bolts together. The free ends of the bolts are carried through the annular part and carry studs lia, which bear on the annular part in the position shown. on the inner wall of the securing sleeve I of the magnet, there are arranged two nose pieces IS, the backs of which are directed towards the electro-magnet 2 and are bevelled off. The end of the armature 6 of the electro-magnet projecting into the securing sleeve I tapers and is provided with a thread, onto which the spring plate l2 and a lock nut 20 are screwed.

If, when the engine is in operation, the driver depresses the pedal q to the left in the drawings then the left hand end of the control rod is is drawn out from the position shown in Figure 3 towards the tapered end of the armature 6. As soon as the tip of the spring tensioned armature engages between the inner ends of the bolts l6 (Fig. 4) the bolts are pressed outwards against the tension of the spring I8. Hereby the control rod is can be displaced to the left by the driver until the two bolts are pressed completely outwards by the tip of the armature and the outer ends of the bolts abut on the nose piece I! of the sleeve I. When the governing bar has reached this position, the separate pumps are set to the full load delivery amount. The nose piece l8 opposes a further displacement of the governing bar to the left, which opposition effect is intended to prevent the driver displacing the control rod still further to the left into the range above the full load position, in which range the control rod sets the injection pump to maximum delivery. The presence of the abutment nose pieces l9 thus render it impossible for the driver to set, during running the pump to deliver an extra amount of fuel, which amount is only intended when starting up the machine, for the purpose of temporary increasing the output of the engine as may be tempted to do for instance when climbing hills by depressing the pedal, for instance, so far to the left that the control rod pushes back the armature of the electro-magnet to the left against the spring which tensions it.

Since the machine might be thermally or mechanically overloaded by setting the injection pump to the maximum deliveryamount during its normal running according to this invention the bolts l6, as soon as the control rod is has reached full load position, are driven outwards by the armature by such a distance, that their free ends, as shown by dotted lines in Figure 4, abut against those surfaces of the nose pieces IQ of the securing sleeve l which face the injection pump. By means of these stop devices, a setting of the injection pump to the excess amount by displacing the governing bar beyond the full load position, is impossible as long as the movable stop or armature has not been withdrawn.

For starting the machine, the switch e is closed. As soon as the pinion of the starter motor engages with the toothed flywheel, the two contacts of the contact strip c1 are connected by the contact bridge piece, which is rocked by the pinion shaft, so that the electromagnet is excited and its armature is withdrawn. As

long as the armature is attracted by the electro-' magnet, the two bolts l6 are also drawn in by the springs l8 'in such a way that when the left hand end of the governing .bar is displaced into the area'range situated above the full load position, their free ends no longer abut on the nose pieces l9, but make free the adjusting pathin this area. As soon as the pinion of the starter motor is disengaged again, the contact bridge piece is rocked back with the lever c1 and the electromagnet is without current. The spring H then tends to return the armature 6 to the left into its initial position, in which it prevents adjustment'of the governing bar beyond the full load position. However, as long as the left hand end of the control rod has not yet returned into this position (full load position) the pointed end of the armature drives the two bolts to the right the stop members can also be constructed inanother way, for instance, by arranging on the armature parts which are moved outwardsby the end of the control rod in such a way that as soon as the control rod might be moved beyond the full load position, they prevent this movement, but on the other hand however, they do not hinder the return movement of the control rod from that area in which it sets the injection pump to deliver the maximum amount of fuel. If the governing of the delivery amount of the injection pump is governed by means of a centrifugal governor, then the arrangement of blocking or stop members is likewise an advantage, for it might occur that the force of the governing springs could overcome the tension ofinternal combustion engines including in combination an electric starter, an injection pump having a control rod, 2. stop to limit the displacement of said rod to correspond to the maximum quantity of fuel delivered for normal engine running, an electromagnet, an armature therefor connected to said stop, said armature being operable"by said electromagnet to displace said stop from said limiting position to allow excess fuel to be delivered, an electrical circuit for supplying current to said starter and said electromagnet, and an electric switch in said circuit and controlling both the starter and the electromagnet.

3. A starting arrangement for fuel injection internal combustion engines including in combi-.

nation arielectric starter, an injection pump having a control rod, a stop to limit the displacement of said rod to correspond to the maximum 'quantity of fuel delivered for normal engine running, an electromagnet, an armature therefor connected to said stop, said armature being operable by said electromagnet to displace said stop from said limiting position to allow excess fuel to be delivered, an electrical circuit for supplying current to said starter and said electromagnet, an electric switch in said circuit and controlling both the starter and the electromagnet, and a spring returning said armature and the stop to its normal limiting position when the starter circuit is broken.

4. A starting arrangement for fuel injection internal combustion enginesincluding in combination an electric starter, an injection pump having a control rod, a stop to limit the displacement of said rod to correspond to the maximum quantity of fuel delivered for normal en-, gine running, and a pinion on the starter shaft, means including an electrical circuit to displace said pinion into engagement with the flywheel of the engine, an electromagnet connected to said circuit, an armature therefor, connected to said stop, said armature being operable by said electromagnet to displace said stop from said limiting position to allow excess fuel to be delivered, and an electric switch insaid circuit and controlling both the starter and the electromagnet. 1

5. A starting arrangement for fuel injection internal combustion engines including in combination an electric starter, an injection pump having a control rod, a stop to limit the displacement of said 'rodto correspond to the maximum quantity of fuel delivered for normal engine running and a pinion on the starter shaft, means including an electrical circuit to, displace said pinion into' engagement with the flywheel of the 4 engine, an electromagnet connected to said circuit, an armature therefor, connected to said stop, said armature being operable by said electromagnet to displace said stop from said limiting position to allow excess fuel to be delivered, an electric switch in said circuit and controlling both the starter and the electromagnet, and means holding said stop in position except when the said electromagnet is excited.

6. A starting arrangement for fuel injection internal combustion engines including in combination an electric starter, an injection pump having a control rod, and a spring pawl carried by the control rod, a fixed abutment on the casing, an electromagnet, an armature therefor, a stop on said armature adapted to displace said pawl into engagement with said fixed abutment, when said control rod is displaced, to limit the displacement of said rod to correspond to the maximum quantity of fuel delivered for normal engine running, said armature-being operable by said electromagnet to displace said stop from said limiting position to allow excess fuel to be delivered, an electrical circuit for supplying current to said starter and said electromagnet, and

an electric switch in said circuit and controlling both thestarter and the electromagnet.

7. A starting arrangement for fuel injection internal combustion engines comprising, in combination, an electric starter, an injection pump having a control member, means to limit the displacement of said member to correspond to the maximum quantity of fuel delivered for normal engine running, electromagnetic means to displace said first-mentioned means from said limiting position, to allow excess fuel to be delivered, electrical switch means, and an electrical circuit including said electromagnetic means, said starter and said switch means, said switch means controlling said starter and said electromagnetic means.

8. A starting arrangement for fuel injection internal combustion engines including, in combination, an electric starter, an injection pump having a control rod, a stop to limit the displacement of said rod to correspond to the maximum quantity of fuel delivered for normal engine running, a pinion on the starter shaft,

means including an electrical circuit to displace said pinion into engagement with the flywheel of the engine, an electromagnet connected to said circuit, an armature therefor connected to said stop, said armature being operable by said electromagnet to displace said stop from said limiting position to allow excess fuel to be delivered, an electric switch in said circuit and controlling said starter, and a second switch in said circuit and operated by said starter to control said electromagnet.

9. A starting arrangement for fuel injection internal combustion engines comprising, in combination, an electrical starter, an injection pump having a control member, stop means operable to limit displacement of said member to correspond to the maximum quantity of fuel delivered fornormal engine running, electrical means to displace said stop means from said limiting position to allow excess fuel to be delivered, and means controlling said starter and said electrical means, said stop means including a movable abutment movable out of limiting position by said electrical means, a stationary abutment, and a movable abutment carried by said control member, said first-mentioned movable abutment, when in the limitingposition, causing said sec- 0nd movable abutment to engage said stationary abutment upon displacement of said control member to limit displacement of said control member, said first-mentioned movable abutment being movable by said electrical means out of the path of movement of said second movable abutment to permit unrestricted movement of said control member.

10. A starting arrangement for fuel injection internal combustion engines includlng,.in combination, an electric starter, an injection pump having a longitudinally displaceable control rod by displacement of which the fuel delivery amount of said injection pump is adjusted, a stop to limit the displacement of said rod in the direction of increasing fuel delivery, said stop being arranged coaxially with said rod, resilient means to keep, during normal running conditions of the engine, the stop in a position corresponding to the desired maximum full load quantity of fuel delivery and avoiding excess fuel delivery, an electromagnet tov displace said stop from said limiting position, an electric switch controlling said stop, said stop being formed as an armature of said electromagnet, and an electric circuit including said electromagnet, said electric starter and said electric switch, said electromagnetbeing so arranged that in the closed position of said switch the armature occupies a.position allowing said' control rod to be placed in its excess fuel position.

11. A starting arrangement according to claim 10 including additional resilient means which automatically adjusts the control rod into its excess fuel position when the first-mentioned resilient means has been overcome by closing the switch. I

.MAX HURST. 7 RICHARD HANLMER.

ERNST RAI'I'HELHUBER. 

